Type 1 diabetes is usually thought to be a defect in insulin production, but endocrinologist  Professor Jerry Greenfield  from the Garvan Institute of Medical Research, NSW is investigating why some people with type 1 diabetes are prone to insulin resistance – and a possible role for metformin.

Can you describe the aim of your research project in 10 words?

To discover factors that predict metformin response in type 1 diabetes.

What have you already discovered about insulin resistance in type 1 diabetes?

We previously demonstrated that people with type 1 diabetes are approximately 30% more insulin resistant than matched non-diabetic controls. The mechanisms contributing to this have not been elucidated. Furthermore, whether insulin resistance occurs at the liver or muscle, or both, is not known.

How does this change what we currently know about insulin resistance in type 1 diabetes?

The proposed study will make clear whether people with type 1 diabetes are insulin resistant at the muscle or liver or both. We will also determine whether metformin, which is used in type 2 diabetes, improves insulin resistance in type 1 diabetes. Our study will determine the factors that predict response to metformin in type 1 diabetes.

What are the possible implications for diabetes management?

If metformin improves insulin resistance in some or all people with type 1 diabetes, there is likely to be benefit in relation to glycaemic control and, almost certainly, cardiovascular risk. Insulin resistance clusters with risk factors for heart disease, so metformin is likely to improves the cardiovascular risk profile in people with type 1 diabetes. Until now, we have not had a systematic methodology to predict who will respond.

What aspect of this current research excites you the most?

The chance to improve the lives of people with type 1 diabetes and reduce the risk of heart disease in this population, who are at high risk.

What’s your Holy Grail – the one thing you’d like to achieve in your research career?

To improve the quality of life and life expectancy of people with type 1 diabetes.

What is your biggest research hurdle?

The major hurdle to undertaking research is time and funding – hence, I am grateful to Diabetes Australia for funding this project. We have no other funds and would be unable to conduct the study without the Millennium Award.

Who has inspired you?

I will forever be grateful to my mentors, Professors Don Chisholm and Lesley Campbell, for their mentorship and guidance.